1. Field of the Invention
The present invention relates to an improved technical device for taking blood samples and for injections, aiming jointly place at protecting the users from possible accidents by pricking or injury with a soiled needle and at allowing a reflux of the blood through the needle during its penetration into the vein, thus performing, by the same mechanism, two functions non-existent in systems of sampling blood employing vacuum tubes for collecting multiple blood samples. A third advantage brought by the invention should, furthermore, be noted, represented by the fact that the intravenous needle lies parallel to the plane of the skin when the system is in position of penetration of the needle on the arm before puncture, while in existing systems, the needles extending at an angle to the plane of the skin which is often awkward for the user who wishes to take a blood sample.
The first, safety function of protecting a user from the risk of injury by the soiled needle is fundamental, being given the present risk represented by diseases transmissible by the blood.
The concept of the system according to the invention allows by the same mechanism the presentation of the needle parallel to the plane of the skin of during the taking of a blood sample and the visual reflux of the blood in the needle (2nd function) during its intravenous penetration, thus giving the operator a much facilitated means for effecting his/her samplings without any risk of pricking and contact with the blood, while the position of the hand holding the system remains very natural.
2. History of the Related Art
It will be recalled that U.S. Pat. No. 3,658,061 (J. P. HALL) describes a protection device applied to a needle intended for the placing of a catheter, which needle, after the catheter has been placed in position and after it has been withdrawn from the vein, remains around the catheter on the patient's body as long as the catheter is functioning. In order to immobilize the needle and to cover its tip for the purpose of avoiding any risk of injuring the patient, there is provided, according to the above-mentioned document, a deformable protector which presents a groove in which the needle is retracted.